The present disclosure relates to a fixing device including a sheet detecting mechanism, an image forming apparatus including the fixing device, and the sheet detecting mechanism installed in the image forming apparatus.
An electrographic image forming apparatus such as a copier or a printer is provided with a fixing device configured to fix a toner image on a sheet. Some fixing devices include a sheet detecting mechanism detecting a sheet to judge whether or not a JAM (paper jamming) has occurred and to count the number of sheets on a basis of a detection result of the sheet detecting mechanism.
For instance, there exists a sheet detecting mechanism including an actuator, a light blocking plate revolving in a body with the actuator, and a detecting part detecting a displacement of the light blocking plate.
In the art described above, however, the actuator is attached to an openable/closable guide member and a position of the actuator shifts subtly from its original position as the guide member is repeatedly opened/closed. If the position of the actuator thus shifts, the position of the light blocking plate provided in a body with the actuator shifts with respect to the detecting part. Due to that, it becomes unable to accurately detect a displacement of the light blocking plate by the detecting part, and the sheet detecting mechanism may possibly cause an erroneous detection.